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RAM air flaps control
#21
I'm not sure if Ford calibrated ram air carburetors differently or not, especially for '71s. By '73 I'm guessing they did due to emissions.

From the factory the carburetors were set up so they would function through a wide range of altitudes and atmospheric conditions and as such were kind of one size fits all.

It really doesn't make any difference if they did or not, jets and power valve changes are easy to do.



“If you can't explain it simply, you don't understand it well enough.”
--Albert Einstein
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#22
I wanted to follow up on this thread. The other day I finally tested the manual air ram control with the EFI system. I was cruising at about 50 mph and when I turned the switch on which opens the air ram flaps the AFR increased to about 15-16 for a split second until the EFI system compensates with more fuel turning it down to 14ish. This is not a WOT so I can control the opening and closing of the flaps manually through the vacuum solenoid I installed. These results indicate that there is definitely more air being pushed down the intake. I tried several times with consistent results. Now, the real question is, does it make a significant power impact and I don't have a real answer for it since I was not measuring acceleration or anything like that. So the jury still is open in regards to it adding power or not. My guess is that it ought to be adding some power since more air and fuel are going down the intake. However, the magnitude of the power increase is debatable.

PS: I ended up using the Dorman's 911-604 vacuum switch activated by a switch inside the car.

        [Image: 20160929_171923_edit2_small.jpg]

1971 M-Code Mach 1 w/Ram Air, 408 stroker, 285/291 0.558" roller cam, Blue Thunder intake, TKO600, Hooker headers with electric cut-offs, FiTech EFI w/ RobBMC PowerSurge pump
Strange center section with Truetrac, 3.5 gear and 31 spline axles, 4-wheel disc brakes
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#23
Do you have any pics of the install?

73 Grandé H Code. Headman long tube headers, T-5 Transmission, 3.70 Traclok, Lowered 1" all around, Aussie 2v heads w/ 2.19 intake, 1.71 exhaust, screw in studs, full roller cam 608/612 lift 280/281 duration LSA 112, Quick Fuel 750 CFM double pumper, AirGap intake.

- Jason


[Image: 082-hot-rod-power-tour-2017-1970-1970s.jpg]
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#24
Here are some pictures I took last night.

The solenoid valve is under that tower brace in the circled area:
[Image: 20190508-214619-edit.jpg]

This is a close-up of underneath the brace. I added the vacuum elbow fitting and cemented it to the solenoid.
The arrows point towards the engine:
[Image: 20190508-214814-edit.jpg]

        [Image: 20160929_171923_edit2_small.jpg]

1971 M-Code Mach 1 w/Ram Air, 408 stroker, 285/291 0.558" roller cam, Blue Thunder intake, TKO600, Hooker headers with electric cut-offs, FiTech EFI w/ RobBMC PowerSurge pump
Strange center section with Truetrac, 3.5 gear and 31 spline axles, 4-wheel disc brakes
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#25
I like flaps .... ooops wrong forum Blush

[Image: siggy.jpg]

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#26
[My guess is that it ought to be adding some power since more air and fuel are going down the intake. However, the magnitude of the power increase is debatable.]
The EFI still monitors the mix and adjusts realtime, so at sustained speed that should not change anything, but this tells you the scoops are doing their job.
At WOT condition, as the air is under pressure, the same will occur, and the limit will be how much your injectors can compensate the need for extra fuel.
I know from the sniper doc, it can cope up to 900 cfm's and max 600HP. so if your EFI has some margin of use, an healthy engine with plenty exhaust, you should get more acceleration power and respons with flaps open when air enters the engine with greater than atmospheric pressure.

Nice test!

73 modified Grandé 351C. Almost done. 
71 429CJ. In progress
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#27
No-cost solution: disconnect the Ram Air flapper control vacuum altogether and block it off - leave the flapper on the end of the air cleaner connected to the engine's thermal-control valve.  You'll always pull cooler air through the Ram Air, but if you need warmer air for cold starts, the flapper on the air cleaner will still open and let warmer under hood air in to help during 'warm-up.'

I see no benefits to to the Ram Air flappers ever closing, aside from helping with cold starts in colder climates.



I have kind of half-assed tested this, as my car's original factory Ram Air flappers had lost their vacuum-ability LONG before I bought it - they're always open.  I don't drive it during cold days, so I can't speak to the whole 'cold-start' aspect, either... not that we have all that many cold days in West Texas.

Eric

[Image: mach1sig2.gif]
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#28
(05-09-2019, 01:40 PM)Mister 4x4 Wrote: I see no benefits to to the Ram Air flappers ever closing, aside from helping with cold starts in colder climates. 

Using an EFI, I don't even think that matters much. Starts as good cold or warm.
Drove also years without the flaps, having a custom ram-air plenum, always had the air coming exclusively from the scoops.

You got to admit that having the flaps is extra cool when functional. I plan add some on my 73, but using a servo to open/close on key-on/off instead of vac.

73 modified Grandé 351C. Almost done. 
71 429CJ. In progress
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#29
I agree that it would be easier just to unplug them. I don't drive it in the rain either which may be another reason to keep the flaps close. Regardless, I like the idea of adding customization like this just because.

        [Image: 20160929_171923_edit2_small.jpg]

1971 M-Code Mach 1 w/Ram Air, 408 stroker, 285/291 0.558" roller cam, Blue Thunder intake, TKO600, Hooker headers with electric cut-offs, FiTech EFI w/ RobBMC PowerSurge pump
Strange center section with Truetrac, 3.5 gear and 31 spline axles, 4-wheel disc brakes
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#30
Oh, don't get me wrong - they're cool beyond words, especially when they work.  I was just throwing that out there.

Having them electronically controlled by a switch or the key is a cool custom feature as well.

I don't think there are issues with driving in the rain - not much in the way of water should really find its way in enough to soak the air filter (I'm guessing) aside from someone splashing the hood with a small pond-sized puddle or something like that.  The air cleaner should have some drainage, I believe.

Eric

[Image: mach1sig2.gif]
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